Question

Francis Crick proposed that certain types of RNA molecules were involved in the incorporation of amino acids into a polypeptide chain in the _____________ hypothesis.

Answer 1

Francis Crick proposed the adaptor hypothesis, which states that transfer RNA (tRNA) molecules act as adaptors to incorporate amino acids into polypeptide chains during protein synthesis, reflecting an evolutionary link in the genetic code.

Step-by-step explanation:

Francis Crick proposed that certain types of RNA molecules were involved in the incorporation of amino acids into a polypeptide chain in the adaptor hypothesis. The transfer RNA (tRNA) is the key molecule that Crick hypothesized to serve as an adaptor, uniting the appropriate amino acid with its corresponding mRNA codon sequence during protein synthesis. The tRNA's role is fundamental as it transfers specific amino acids to the growing polypeptide chain at the ribosome, having an anticodon sequence that pairs with the mRNA codon and a site to bind the corresponding amino acid. This hypothesis underscores the evolutionary significance of tRNA in the origin and evolution of the genetic code, reflecting a time when amino acids may have been directly linked to RNAs without enzymatic intervention, a notion supported by subsequent discoveries in molecular biology and evolution of the genetic code.